Emerging applications require materials with sophisticated control over the 3D architecture at different length-scales. For example, engineering an adequate average pore size distribution, porosity, and tortuosity would reduce pressure drop losses, improve mass transport and reaction distribution, decrease ohmic resistance, and maintain a low weight. In this program, we design, simulate, and manufacturing architected porous electrodes with various degrees of hierarchical organization. Examples of ongoing projects include:

• Simulating electrochemical phenomena within porous electrodes with pore network modeling. Developing predictive modeling frameworks based on evolutionary algorithms and 3D simulations.
• 3D printing of electrodes and flow fields to elucidate structure-performance relationships.
• Developing versatile and scalable synthetic platforms (e.g. phase separation, hydrogen bubble templating) to conventional fiber-based electrodes.

The interfacial properties of solids and the interacting fluid define a number of important characteristics, such as electrochemically-active surface area, intrinsic activity, stability, and selectivity. In this program, we employ electrografting and other techniques to grow thin films of selected polymers with tailored properties onto the surface of model electrodes and porous materials. Examples of ongoing projects in this space include:

• Developing kinetically active and selective electrode interfaces for flow batteries.
• Engineering thin-film ionomers for fuel cells and electrolyzers.
• Developing porous electrode interfaces with precisely controlled wettability.

Traditional electrochemical diagnostics are based on measuring the voltage response to an applied current (or vice versa). However, our ability to deconvolute the underlying thermodynamic, kinetic, and transport processes is still quite limited – it remains a black box. In this program, we are interested in understanding the performance of materials during operation through visualization of local properties (i.e. concentration, flow distribution, temperature). Pursuant to this goal, we employ advanced imaging techniques, namely neutron imaging and X-ray tomographic microscopy, tin combination with electrochemical diagnostics. Examples of ongoing projects include:

• Neutron imaging of electrochemical systems to visualize local concentrations.
• X-ray tomographic microscopy to visualize the electrode 3D structure.
• Electrochemical diagnostics to assess the full device performance.